Thread-cutter for bag-sewing machines



.l. 0. BAKKE.

THREAD CUTTER FOR BAG SEWING MACHINES.

APPLICATION FILED AUG-5, 1915.

1,342, 1 50. l Patented June 1, 1920.

2 SHEETSSHEET 5 1 I/NkfjTQ/P 5y i x I 1. 0. BAKKE. THREAD CUTTER FOR BAG SEWING MACHINES.

.APPLICATION FILED AUG-5| 1915.

1 ,342, 1 50. Patented June 1, 1920.

2 SHEETS-SHEET 2 bility of injury to the operatives.

JULIUS O. BAKKE, OF MINNEAPOLIS, MINNESOTA, ASSIGNOR TO 'WASHBURN-GROSBY COMPANY, OF MINNEAPOLIS, MINNESOTA, A CORPORATION OF MINNESOTA.

THREAD-CUTTER. roa BAG-SEWING MAcnnvEs.

Specification of Letters Patent.

Patented June 1, 1920.

Application filed August 5, 1915. Serial No. 43,740.

To all whom it may concern:

Be it known that I, JULIUS O. BAKnE, a citizen of the United States, and resident of Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Thread-Cutters for Bag-Sewing Machines, of which the following is a specification.

This invention relates to improvements in thread-cutting mechanism for sewin machines, and more particularly has re erence to such mechanism as applied to machines for sewing filled bags, as those in which flour and similar materials are packaged.

More specifically stated, the present invention is designed as an improvement on the construction of thread cutter illustrated and described in United States Letters Patent No. 768,111, Burghardt, dated August 23, 1904. That construction has proved practical for the purposes intended, but the cutter blades are so exposed that unless great care is exercised by operatives .ofthe machine equipped therewith there ispossi- Moreover, the position of the Burghardt cutter in relation to the sewing mechanism is somewhat remote therefrom, the point of severance of the thread being such that a considerable length of the chain of stitches remains at the marginal portions of the bags afterthe chain is cut. This involves material waste of thread. The present invention, therefore, has as its primary object to provide a construction of thread-cutting mechanism which shall be safer to operate than that of the Burgha'rdt patent, thereby insuring to the operatives freedom from injury by the cutters; and furthermore, to effect such a reorganization of the cutting mechanism with relation to the sewing mechanism as will obviate a waste of thread when the chain of stitches is severed. This avoids protruding ends of any considerable length at the bag margins and imparts to the closed mouths of the packages a neat appearance when sewed.

The invention further aims to provide cutting mechanism of the class mentioned which is simple and highly efficient, light in construction, and one which can be maintained easily in proper working condition.

Having these general objects in view, and others which will appear as the nature of the improvements is better understood, the invention consists substantially in the novel construction, combination and arrangement of parts hereinafter fully described, illustrated in the accompanying drawings, and pointed out in the appended claims.

In the drawings Figure l is a side elevation of a bag-sewing machine equipped with thread-cutting mechanism constructed in accordance with the present invention, only those portions of the sewing machine being illustrated as are necessary for an understanding of the invention.

Fig. 2 is a sectional plan view on the line 2-2 of Fig. 1.

Fig. 3 is a detail elevation of the needle plate of the sewing mechanism.

Fig. 4 is a view in elevation, similar to Fig. 1, observing the sewing mechanism at the side opposite to that seen in Fig. 1, parts being illustrated in section.

Fig. 5 is a view similar to Fig. 4, the cutting mechanism being' illustrated as closed or in the condition it assumes for severing the thread. I

Fig. 6 is an enlarged detail sectional view of the cutter-supporting head and the cutters associated therewith.

Fig. 7 is a vertical sectional view "of the cutter-supporting head, the line of section being through the pivotal point of the cutter blades. 7

Referring now in detail to the accompanying drawings, the numeral 1 designates a sewing head, which may be of any approved construction, the same being disposed so that its needle bar 2 operates in a horizontal plane. This head includes the usual presser-foot 3 which cooperates with struction of thread cutter illustrated in the Burghardt Patent, No. 768,111. This construction includes a drive shaft 6 at the upper end of which is located a pulley 7 having a belt 8 for transmitting motion to the driving mechanism 9 of the sewing head. Reference is to be made to the Burghardt patent for a more complete understanding of the specific driving mechanism included therein. For the purposes of the present invention it is but necessary to state that the drive shaft 6 at its lower end is provided with a suitable clutch by which rotation may be imparted to the shaft 6when it is desired to actuate the sewing head 1. As

illustrated in the Burghardt patent, thcthread-cutting mechanism is rendered inoperative while the sewing head is being actuated, and when the sewing operation is complete thesewing mechanism comes to rest and the thread-cutting mechanism is immediately set in motion. The conditions of operation of the thread cutter in the present instance are the same as those just referred to, a connecting rod 10 being interposed between the clutch at the lower end of the drive shaft-6 and a contact arm 11 by means .of which the thread-cutting mechanism becomes operative. As is disclosed in the 'Burghardt patent, the contact arm 11 is sleeved uponla collar 12 forming part of the cone member 13 of a clutch, a set screw 14, or its equivalent, being employed for holding the contact arm 11 in tight engageclearly appears from the disclosure of the Burghardt patent, when the power clutch at the lower end of the drive shaft 6 is operated to remove the'power from said shaft,

the clutch member 13 is brought into engagement with the clutch member 15 by the connecting rod 10. But as the shaft 6 continues to operate under its momentum the engagement of the member 15 with the member 13, causes the latter to rotate, and this re sults in the swinging of the contact arm 11 in the direction of the arrow illustrated in Fig. 2.

The present invention seeks to provide an improved form of thread-cutting mechanism with a view to overcoming the objectionable features of the thread-cutting mechanism of the Burghardt patent. Therefore, a radical departure is made in the construction of the cutting members and the manner in which the latter act upon the chain of stitches. To this end a cutter-supporting head. 17 is employed, which head is substantially L-shaped, one end thereof being provided with a bore 18 of suitable configuration, and the other end being slotted, as at 19, in order to receive and house a pair of cutter blades .20. These blades 20 are provided with shear 1nembers21 which cooperate with each other in a scissors-like fashion, the blades 20 being pivoted in the slot 19 by means of a screw 22 having adjacent to its head a coil spring 23 whereby to exert the requisite tension upon the cutter blades.

limits the opening or separating movement of the shear members 21 and insures their entrance into the slot 26 when moved there-' n. bers a vertically-disposed slot 26 is formed For automatically closing these memin the needle plate, 4 of'the sewing head, said slot'being directly opposite the shear members 21, and at a predetermined time said members 21 are introduced into said slot.

The upper and lower ends of said slot are beveled, as at 27, said beveled ends cooperating with the rounded outer edges of the shear members, and as the latter are forced into the slot 26 it is apparent that the beveled ends of said slot force the shear members together and cause the latter to sever the chain of stitches. It will be observed one side of the line of seam and-the needle plate 4 with its slot 27 occupies a position at the opposite side thereof. The shear members travel across the line of the seam and project away from the position normally occupied by the ma chine operator, so that in performing the cutting operation the shear members are moved away from the operator. This reduces liability of injury to the operator to a minimum.

A U-shaped actuator 28 is employed for that the shear members .21 are arranged at imparting motion to the cutter-supporting head. One leg of this actuator is longer than the other, the actuator being mounted for reciprocation in the standard 29 of the sewing machine. The free end of the longer leg 30 of the actuator is received by the bore 18 of the head 17, said head being adjust ably mounted upon the leg 30 by means of set screws 31, or their equivalent. The shorter leg 32 is encircled by a coil spring 33 which is interposed between the standard 29 and a washer 34 at the free end of said leg. When, therefore, movement is imparted to the actuator 28 for closing the shear members 21, the spring 33 becomes compressed and upon proper release of the actuator 28 in the manner hereinafter described the spring 33 exerts its force to project the actuator 28 in an outward direction and thereby to withdraw the shear members 21 from the slot 26 of the needle plate.

Extending rearwardly from the standard 29 is a supporting bar 35 to which bar an operating lever 36 is pivoted, as at 37. Interposed between the upper end of said lever 36 and the actuator is a link 38 whereby movement is imparted to the actuator from the lever 36. The lower end of said lever36 extends into the path of movement of the contact arm 11 and as the latter swings in the direction indicated by the arrow in Fig. 2 it engages the lever 36 and thereby operates the actuator 28 for introducing the shear members 21 into the slot 26. The reverse movement of the contact arm 11 is limited by a depending stop 39, said stop being carried by the bar 35.

If it be desired to cushion the movement of the cutter-supporting head 17' a washer 40 of suitable material may surround the leg 30 of the actuator 28 at a point between The cutter-supporting head and the sewing lead.

From the foregoing description the operation of the herein-described cutter will be apparent, and briefly stated is as follows:

Assuming that the bag mouth has been closed by the sewing mechanism and the power clutch operated to disengage the same from the shaft 6, the contact arm 11 is actuated in the manner previously set forth herein and thereby is brought into engagement with the lower end of the lever 36. This lever is thus swung upon its fulcrum and the actuator 28 is drawn rearwardly compressing the spring 33 and forcing the shear members 21 into the slot 26. The members 21 thus move toward each other and sever the chain of stitches, which in the opposite direction thereby withdrawing the shear members from said slot. This movement of the actuator 28 shifts the position of the lever 36, and the contact arm 11 moves in a reverse direction to that which it follows under the momentum of the drive shaft 6. Its reverse movement, however, is limited by its contact with the depending stop 39. When the position of the parts has been restored in the manner just described the sewing mechanism again may be put in operation for closing the mouth of the following bag, and when this has been effected the chain of stitches may be severed as specified. The periodic operation of the cutter will continue solong as the bags are passed through the sewing machine.

Having thus described the invention, what is claimed as new, and desired to be secured by Letters Patent, is:

1. A thread cutter of the class described, comprising a plurality of cutters mounted for relative movement, an element arranged in juxtaposition to said cutters and provided with a slot into which the cutters are introduced and which coiiperates with said cutters to effect the cutting operation, and

means for establishing relative movement between said cutters and said element whereby to introduce the cutters to and remove the same from said slot.

2. A thread cutter of the class described, comprising a plurality of pivoted cutters, an element arranged in juxtaposition to said cutters and provided with a slot into which the cutters are introduced and which cooperates with said cutters to effect the cutting operation, and means for establishing relative movement between said cutters and said element whereby to introduce the cutters to and remove the same from said slot.

3. A thread cutter of the class described, comprising a plurality of pivoted cutters,

an element arranged in juxtaposition to said cutters and provided with a slot into which the cutters are introduced and which cooperates with said cutters to effect the cutting operation, means for establishing relative movement between said cutters and said element whereby to introduce the cutters to and remove the same from said slot, andmeans for actuating said. cutters to open the same when released from said slot.

4 A thread cutter of the class described, comprising a plurality of pivoted cutters, an element arranged in juxtaposition to said cutters and provided with a slot into which the cutters are introduced and which cooperates with said cutters to effect the cutting operation, means for establishing relative movement between said cutters and said element whereby to introduce the cutters to and remove the same from said slot, means for opening the cutters when the latter are released from said slot, and means for limiting the degree of separation of the cutters.

5. A thread cutter of the class described, comprising a cutter support, a plurality of cutters associated therewith and mounted for relative movement, a stationary element arranged in juxtaposition to said cutter support and provided with a slot into which the cutters are introduced and which cooperates with said cutters to effect the cutting operation, and means for establishing relative movement between said cutter support andsaid element whereby to introduce the cutters to and remove the same from said slot.-

6. A thread cutter of the class described, comprising a cutter support, a plurality of cutters associated therewith and mounted for relative movement, a stationary element arranged in juxtaposition to said cutter supportand provided with a slot into which the cutters are introduced and which 00- operates with said cutters to eflect the cutting operation, means for establishing relative movement between said cutter support and said element whereby to introduce the cutters to and remove the same from said slot, and means for actuating the cutters to open the same after their removal from said slot.

7. A thread cutter of the class described comprising a slotted cutter support, a plurality of cutters arranged within the slot of said support and pivotally mounted therein, a slotted element arranged in juxtaposition to the cutter support and adapted to receive said cutters for effecting the cutting operation, and means for efi'ecting relative movement between said slotted element and the cutter support.

8. A thread cutter of the class described comprising a slotted cutter support, a plurality of cutters arranged within the slot of said support and pivotally mounted therein, a slotted element arranged in juxtaposition to the cutter support and adapted to receive said cutters for effecting the cutting operation, means for effecting relative movement between said slotted element and the cutter support, and means for opening said cutters when the latter are removed from said slotted element.

9. A thread cutter of the class described comprising a plurality of pivoted cutters, a slotted element arranged in juxtaposition to said cutters and provided with beveled portions for cooperation with said cutters to close the latter, means for introducing said cutters into said slotted element, and means for removing said cutters therefrom.

10. A thread cutter of the class described, comprising a plurality of cutter members, a stationary element arranged in juxtaposition to said cutters and cooperating with the latter for closing the same, means for moving the cutters into cooperative relation with said stationary element for closing the cutters and effecting the cutting operation, and means for releasing the cutters from cooperative relation with said stationary element.

11. A thread cutter of the class described, comprising a plurality of pivoted cutters, a stationary element arranged in juxtaposition to said cutters and cooperating with the latter for closing the same, means for moving said cutters into cooperative relation with said stationary element to close the cutters and efiect the cutting operation,

means for removing the cutters from coop erative relation with said stationary element, and means for restoring the cutters to operating therewith for actuating the cut-v ters to effect the cutting operation, positively-acting means for moving the cutters into cooperative relation with said cutteractuating means, and resilient means for releasing the cutters from cooperative relation with said actuating means.

14. A thread cutter of the class described, comprising a plurality of pivoted cutters,

' means for actuating the latter to effect the cutting operation, positively-driven means for moving the cutters into cooperative relation with said actuating means, means acting in opposition to said positively-driven means for releasing said cutters from cooperative relation with said actuating means, and means for restoring the cutters to noncutting position when released from said actuating means.

15. A thread cutter of the class described, comprising a plurality of pivoted cutters, a slotted element arranged in juxtaposition to said cutters and cooperating with the latter for eifecting the cutting operation, positively-driven means for introducing the cutters into said slotted element, and means acting in opposition to said positivelydriven means for removing the cutters fromsaid slotted element.

16. A thread cutter of the class described, comprising a plurality of pivoted cutters, a slotted element arranged in juxtaposition to said cutters and cooperating with the latter for effecting the cutting operation, positively driven means for introducing the cutters into said slotted element, means acting in opposition to said positivelydriven means for removing the cutters from said slotted element, and means for restoring the cutters to non-cutting position when released from said slotted element.

17. A thread cutter of the class described, comprising cutting mechanism, actuating means adapted to receive and with which the cutting mechanism is engaged to effect hani m a d ai a uating means, an

means for restoring said cutting mechanism to non-cutting position when removed from said actuating means.

18. A thread cutter of the class described, comprising cutting mechanism, actuating means adapted to receive and with which the cutting mechanism is engaged to effect the cutting operation, said cutting mechanism beingremovable from engagement with said actuating means, an actuator for establishing movement between the cutting mechanism and said actuating means, means for positively operating the actuator teetfect the cutting'operation, means acting in opposition to said positively-acting means for moving the actuator to disengage the cutting mechanism from its actuating means, and means for restoring said cutting mechanism to non-cutting position when removed from said actuating means.

I 19. A thread cutter of the class described,

comprising a plurality of pivoted cutters, a slotted element arranged in juxtaposition'to said cutters and cooperating with the latter for effecting the cutting operation, an actuator to which said pivoted cutters are connected and adapted to establish relative movement between said cutters, and said slotted element, positively-acting means for operating the actuator to introduce the cutters to said slotted element, and means acting in opposition to said positively-acting means for operating the actuator to release the cutters from said slotted element.

' 20. A thread cutter of the class described, comprising a plurality of pivoted cutters, a slotted element arranged in juxtaposition to said cutters and cooperating with the latter for effecting the cutting operation, an actuator to which said pivoted cutters are connected and adapted to establish relative movement between said cutters and said slotted element, positively-acting means for operating the actuator to introduce the cutters to said'slotted element, means acting in opposition to said positively-acting means for operating the actuator to release the cutters from said slotted element, and means for restoring the cutters to non-cutting position when so released.

21. A thread cutter of the class described, comprising a plurality of cutters, a reciprocatory actuator to which said cutters are connected, means adjacent to said cutters adapted to cooperate therewith for effecting the cutting operation, positively-acting means for moving the actuator in one direction to establish cooperative relation between the cutters and said actuating means, and means for moving the actu tor n the opposite direction to release-the cutters from cooperative relation with' said actuating .70 mechanism carried by one leg thereohme'ans cooperating with said cutting'mechanism to effect the cutting operation, means for moving the actuator to'establish the cooperative relation between said cutting mechanism and said actuating means, and means carried by the other leg of the actuator for operating the latter to release the cutting mechanism from its cooperative relation with said actuating means. I

28. A thread cutter of the class described, comprising a U-shaped actuator mounted for reciprocatory movement, cutting mechanism carried by one leg of said actuator, means adapted to cooperate with said cutting mechanism to effect the. cutting operation, means fo mo ng t ua or in o direction to establish cooperative relation between said cutting mechanism and said actuating means, and means associated with the other leg of said actuator for moving the latter in the opposite direction torelease the cutting mechanism from cooperative re lation with said actuating means,

24 A thread cutter of the class described,

comprising a slotted cutter support, a plu--" rality of cutters mounted for relative movement within the slot of said support, means arranged in "juxtaposition to saidsupport and cooperating with the cutters to effect the cutting operation, means for establishing relative movement between the cutter support and said actuating means, and a spring for restoring the cutters to non-cutting position when released from cooperative relation with said actuating means.

25. A thread cutter of the class described, comprising a slotted cutter support, a plurality of cutter blades pivotally 'mounted within the slot of said support, a slotted element arranged in juxtaposition to said cutter support and cooperating with said cutter blades to effect the cutting operation, means for establishing relative movement between said cutter support and said slotted element, a spring connected to said cutter blades for restoring the latter to non-cutting position when released from cooperative relation with said slotted element, and a stop.

means for effecting relative movement beactuating said cutters toward and from said needle plate. 7

' 28. In a sewing machine, the combination with thesewing head thereof and the needle plate associated therewith, said needle plate being provided with a slot, of a plurality of pivoted cutters arranged adjacent to said slot and mounted for movement relative thereto, means for introducing said cutters into said slot for effecting the cutting operation, means for moving the cutters from said slot, and means for restoring the cutters to non-cutting position when removed from said slot.

29. In a sewing machine, the combination with the sewing head thereof and the needle plate associated therewith, said plate being provided with a slot, of a cutter support arranged adjacent to said needle plate, a

plurality of pivoted cutters carried by said cutter support, saidneedle plate cooperatand said needle plate, and means for restoring the cutters to non-cutting position when the same are removed from said slot.

30. In a sewing machine, the combination with the sewing head thereof, of cutting mechanism arranged at one side of the line ofthe seam, means for moving said cutting mechanism across the line of the seam, and means arranged at the opposite side of the line of the seam and with which said cutting mechanism cooperates for actuating the cutting mechanismto cut the chain of stitches.

31. In a sewing machine, the combination with the sewing head thereof, of a cutter support arranged at one side of the line of the seam, a plurality of cutters mounted in said support, means for movingsaid cutter support across the line of the vseam, and a slotted element arranged at the opposite side of theline ofv the seam, the slot of said element being adaptedto receive said outters for actuating the latter to cut the chain of stitches;

JULIUS ,0. BAKKE.

Witnesses:

H. OB. HARDING, MA nLLn GILLIAM. 

